feat(content): add products, services and legal pages

- Add /products/, covering the one product actually in service. It is
  written to match reality rather than padded out to look like a matrix.
- Add /services/, describing the work taken on and, deliberately, the
  work that is not a good fit.
- Add the privacy policy and terms, linked from the footer. Both describe
  what the site actually does — no cookies, no analytics — and carry
  TODO notes for the parts needing legal review.

docs/en-gb/legal/terms.md

@@ -0,0 +1,87 @@
+---
+title: Terms of Service
+description: The terms governing use of the OnixByte website, our published tools and our open-source projects.
+sidebar: false
+outline: false
+---
+
+<!-- TODO(legal): written to describe how the site and tools actually behave,
+but it has not been reviewed by a lawyer. Have it checked before relying on it —
+particularly the liability section. -->
+
+**Last updated: 25 September 2026.**
+
+These terms govern your use of this website and of the free tools we publish.
+They are issued by Changsha Onix Byte Technology Co., Ltd ("we", "us"), the
+operator of onixbyte.com and onixbyte.cn. By using the site or the tools, you
+agree to them.
+
+## What these terms cover
+
+They cover this website and the tools we host and offer free of charge, such as
+Dev Lab.
+
+They do **not** cover our open-source projects — see "Open-source projects"
+below — and they do not govern any commercial engagement you have with us.
+Work we do for a client is governed by the contract for that engagement.
+
+## Use of the site and tools
+
+You may use the site and the tools for any lawful purpose. You may not:
+
+- attempt to disrupt or overload the service, or access it by automated means in
+  a way that degrades it for others;
+- attempt to gain access to systems or data you are not authorised to access;
+- use the tools to process material that is unlawful, or that you do not have
+  the right to process.
+
+## Your data stays yours
+
+Anything you paste into our browser-based tools remains yours and remains on
+your machine. We claim no rights over it, and we never receive it. See the
+[Privacy Policy](/legal/privacy) for the detail.
+
+## Tools are provided as they are
+
+The tools are offered free of charge and without warranty of any kind. They are
+utilities, not professional advice:
+
+- Results from the JSON tooling are a convenience for inspecting data. Verify
+  anything you intend to rely on against the source data.
+- The BMI calculator produces a general-purpose figure. It is not medical
+  advice, and it is not a substitute for consulting a qualified professional.
+
+## Open-source projects
+
+Our open-source projects — including the libraries we publish on Maven Central
+and GitHub — are released under the licence stated in each repository. That
+licence governs your use of that code, and it takes precedence over these terms
+in respect of it. If there is any conflict between these terms and an
+open-source licence, the open-source licence wins.
+
+## Intellectual property
+
+The OnixByte name, logo and the design of this website belong to us. The
+open-source code we publish is licensed to you under the terms described above.
+
+## Limitation of liability
+
+The site and the free tools are provided "as is" and "as available". To the
+fullest extent permitted by law, we are not liable for any indirect or
+consequential loss arising from your use of them, or from their being
+unavailable.
+
+Nothing in these terms excludes liability that cannot lawfully be excluded.
+
+## Changes to these terms
+
+We may update these terms as the site and tools change. The date at the top
+shows when they were last revised. If you keep using the site after a change,
+that means you accept the revised terms.
+
+## Contact
+
+**business@onixbyte.com**
+
+Changsha Onix Byte Technology Co., Ltd
+Hunan Province, China